Antidepressants are a category of medications used in the treatment process for depressive disorders, anxiety disorders, eating disorders, chronic pain and addiction. The effectiveness of [subject] in adults has been the subject of inconsistent and frequently contentious research.
According to a 2018 study, 21 different antidepressant classes were marginally superior to placebos for treating people with acute depression. On the other hand, other researchers stated that the placebo effect may contribute to most of the drug’s efficacy.
We can confidently claim that antidepressants have more negative effects than positive ones after performing considerable research. They result in apoptosis, irreversible neuronal damage, and dysregulation of serotonin adaptive processes, according to research and, It is crucial to keep in mind that individuals with severe depression or anxiety symptoms were the subjects of these studies, therefore general populations without a formal diagnosis cannot use the results.
On 14th June 2023, the World of Statistics released a report about antidepressant users. The lowest antidepressant consumption rate in the world was discovered in India, where 9 out of every 1000 persons used them. In Iceland, it was found that 161 out of 1000 people were reported to be antidepressant users, making it the country with the highest number of users.
India has seen a 20% rise in the intake of antidepressants, with Prozac being one of the most widely prescribed and used medications as of now, which is concerning despite the low numbers (keeping in mind the strength of the Indian population)Despite the low numbers (considering the size of the Indian population), antidepressant use has increased by 20% in India, with Prozac currently being one of the most commonly prescribed and used drugs. The rates of depression or anxiety are found to be around 39.3%, which means that 4 in 10 adults in India were reported to have some form of depression or anxiety.
So, are antidepressants effective? What are the different types of antidepressants? What are their side effects?
Research behind Antidepressants
Antidepressants may take 4 to 8 weeks to start enacting the symptoms. Did you know that different antidepressants work differently based on person to person? That is, not all antidepressants cause symptom relief and proper response for all people. and this response differs based on the patient and their history.
Looking into the effectiveness of antidepressants, research has observed around one-third of people accomplish full remission, one-third may experience response, and the remaining are non-responders.
There exist chances of partial remissions which is a powerful predictor of relapse rates. These rates are about 3 to 6 times higher in people with partial remission of their mental condition also, Partial remission can include residual symptoms such as low mood, anxiety, difficulty sleeping, tiredness and loss of interest. In addition, an antidepressant may also lose their effectiveness in long-term maintenance therapy.
According to American Psychiatric Association guidelines, if antidepressants don’t work within 6 to 8 weeks of treatment a switch in medication of the same class and then to a different class is recommended. Studies have shown that people who don’t respond to SSRIs have a 12% to 86% chance of responding to a new drug. But it is to be remembered that the greater number of antidepressants the patient has tried the lower the chances of response to a new drug.
Augmentation Therapy
In case of partial response to antidepressants, adding a drug from a different class may be effective and this form of treatment is called augmentation therapy. Additional medications used in augmentation therapy are given below:
- Lithium and Thyroid
- Dopamine agonists
- Sex steroids
- NRIs
- Glucocorticoid-specific agents
- Newer anticonvulsants
- Psychostimulants
- Modafinil
Types of Antidepressants
1. Selective Serotonin Reuptake Inhibitors
Selective serotonin reuptake inhibitors (SSRIs) restrict serotonin reabsorption into the presynaptic cell so they also raise the amount of serotonin in the synaptic cleft which are available for binding with postsynaptic receptors thereby causing an increase in neurotransmitter in extracellular level. In many nations, SSRIs are the antidepressants that are most frequently prescribed. The effectiveness of SSRIs in treating mild to moderate depression has been contested.
2. Selective-Norepinephrine Reuptake Inhibitors
Serotonin-norepinephrine reuptake inhibitors (SNRIs) are known as potent inhibitors of the reuptake of serotonin and norepinephrine. These neurotransmitters are known to have a substantial impact on mood.
Membrane proteins called the human serotonin transporter (SERT) and norepinephrine transporter (NET) reabsorb serotonin and norepinephrine. By treating a wider spectrum of symptoms, balanced dual inhibition of monoamine reuptake may be superior to other antidepressant medications.
SNRIs can be used for treating the following conditions:
- Depression and menopausal symptoms
- Anxiety disorders
- Obsessive-compulsive disorders (OCD)
- Attention deficit hyperactivity disorder (ADHD)
- Chronic neuropathic pain
- FMS)
3. Serotonin Modulators and Stimulators
SMSs (serotonin modulators and stimulators) are a class of medication having a multimodal action that is particular to the serotonin neurotransmitter system. They are also occasionally referred to as “serotonin modulators” or “serotonin modulators”. SMSs specifically inhibit serotonin reuptake while modulating one or more serotonin receptors, and the phrase was created to describe the serotonin reuptake inhibitor (SRI), a partial agonist of the 5-HT1A receptor, and antagonist of the 5-HT3 and 5-HT7 receptors actions of the serotonergic antidepressant Vortioxetine.
4. Serotonin Antagonists and Reuptake Inhibitors
While primarily employed as antidepressants, serotonin antagonists and reuptake inhibitors (SARIs) also have hypnotic and anxiolytic properties. Also, they work by blocking the reuptake of dopamine, norepinephrine, and/or serotonin through antagonizing serotonin receptors like 5-HT2A. Most also function as antagonists of the 1-adrenergic receptors, the phenylpiperazine class of chemicals is where most of the SARIs that are now on the market come from. Trazodone and Nefazodone are some of them.
5. Tricyclic Antidepressants
By inhibiting the serotonin transporter (SERT) and the norepinephrine transporter (NET), respectively, most tricyclic antidepressants (TCAs) act primarily as serotonin-norepinephrine reuptake inhibitors (SNRIs), which enhances neurotransmission. Notably, the TCAs have weak dopamine transporter (DAT) affinity, apart from amineptine, and are hence ineffective as dopamine reuptake inhibitors (DRIs). Also, the level of side effects for TCAs and SSRIs is comparable.
6. Monoamine Oxidase Inhibitors
Chemicals called monoamine oxidase inhibitors (MAOIs) stop the monoamine oxidase enzyme family from working. They have a long history of being used as medicines that doctors prescribe to treat depression. They work especially well to treat atypical depression. Parkinson’s disease and several other illnesses are also treated using them.
MAOIs have traditionally been used as a last resort, only when other antidepressant drug classes (such as selective serotonin reuptake inhibitors and tricyclic antidepressants) have failed, due to the possibility of deadly food and drug interactions.
7. Tetracyclic Antidepressants
The 1970s saw the initial introduction of the tetracyclic antidepressant (TeCA) class of medications. They are named after the four atomic rings that make up their chemical structure and are related to tricyclic antidepressants (TCAs), which consist of three rings of atoms.
Adverse Side Effects of Antidepressants
Antidepressants, though help in treating mental health conditions, may also produce adverse side effects:
- Antidepressants can cause serotonin toxicity, this is a condition that occurs when excess serotonin is present in the system causing mania, restlessness, agitation, difficulty sleeping, confusion, and other emotional symptoms.
- MAOIs when taken with food containing high levels of tyramine can cause lethal cases of hypertensive crisis.
- Elders who use tricyclic and SSRIs may experience drug-induced QT prolongation. This condition causes abnormal heart rhythm which can lead to cardiac arrest in the person.
- The possibility that some antidepressants can promote suicidal tendencies needs to be investigated further.
- A few other side effects include discontinuation syndrome, antidepressant-induced mania, sexual dysfunction, emotional blunting, weight problems, bone loss, risks during pregnancy and in certain cases higher chances of death.
